David,
Your questions are too broad to be answered via a form post. Why don't you want to log a support case and arrange a screen share session with a support engineer?
Brief replies to your queries are:
1. You can only create a transition project from a page, but not from a paragraph on the page. After a transaction project has been created you can review: add/remove the content that you need to send to a translation service.
2. You can create a multi-language translation project to translate more than one language at the time
Managing Translation Projects
3. Most likely it is a project configuration issue. I suggest bringing it to a screen share session with Adobe AEM support
4. You might need to configure a desire copy/past behavior:
paste-default
paste-plaintext
paste-wordhtml
Configure the Rich Text Editor